1. Field of the Invention
The present invention generally relates to soft handoffs between mobile switching centers that use different protocols.
2. Background of the Related Art
Mobile radio communication systems are used in everyday life. Garage door openers, remote controllers for home entertainment equipment, cordless telephones, hand-held walkie-talkies, pagers, and cellular telephones are all examples of mobile radio communication systems. For example, cellular radio systems provide high quality service that is comparable to that of landline telephone systems.
Some cellular telephones communicate with base stations (with antennas at a fixed location) that are located proximate to the cell phone. However, as a user transports a cell phone, the base station which is proximate to the cell phone changes. Accordingly, a cell phone must then switch or change the base station it is communicating with to receive a better radio signal. This changing allows cell phones to continue conversations during geographic movement.
However, all base stations are not compatible. For instance, two base stations, which are located proximate to each other, may be owned by separate companies and operate using different protocols. Nevertheless, it is often necessary for a cell phone to change base stations which do not use the same protocol. When this occurs, calls are often disconnected or there is an interruption of service. This can be very annoying to a user of a cell phone. Accordingly, there is a need for relatively transparent changing of base stations when the base stations use different protocols.